F pilus as f+ antigen.
Specific aggregate formation of F pili was observed, by electron microscopy, in a mixture of male Escherichia coli (or of isolated F pili) and anti-f(+) serum. Cellular appendages other than F pili never showed such aggregation when mixed with anti-f(+) serum. The f(+) agglutinability of male cells, as well as F piliation, was sensitive to mechanical agitation. The f(+) agglutination was inhibited when appropriate numbers of phage M12, capable of attaching to F pili, were mixed with the male culture before the addition of anti-f(+) serum. Correlation between f(+) agglutinability and the extent of F piliation was observed. It was concluded that the F pilus is the structure of the f(+) antigen and is responsible for f(+) agglutination.
D000372:Agglutination Tests; D000937:Antigen-Antibody Reactions; D000941:Antigens; D003090:Coliphages; D004926:Escherichia coli / Q000276:immunology*; D006386:Hemagglutination Tests; D008854:Microscopy, Electron
D000941:Antigens